(Yicai Global) Feb. 9 -- Hong Kong regulators have doubled down on efforts to clamp down on initial coin offerings, again warning cryptocurrency platforms in the special administrative region against such activities and highlighting the risks of virtual currency trading.

Hong Kong's seven major digital currency issuers have so far complied with guidance issued last year which called on them to refrain from any cryptocurrency trading that could be deemed as unlicensed securities, the Securities and Futures Commission said in a statement.

Some of the platforms concerned have also stopped trading of cryptocurrencies.

The SFC will continue to monitor the market and take legal action when necessary to prevent fraud or suspicious fundraising activities related to ICOS, the commission's chief executive Ashley Alder noted.

Mainland China shut down all bitcoin exchange platforms in the second half of last year, but some exchanges are still engaged in such activities through the establishment of websites or servers overseas.

Regulatory authorities on the mainland will implement more stringent restrictions on virtual currency platforms and crack down on overseas websites aimed at Chinese investors, reported Financial News, a newspaper affiliated to central bank, the People's Bank of China, on Feb. 5.